In 1998, the Cancer Center Executive Committee agreed to plan the establishment of a Stem Cell Biology Core. This Shared Resource will provide access to high quality murine and human hematopoietic stem and progenitor cells based on investigator requests. Such access is invaluable in facilitating and extending the work of investigators involved in the study of transforming oncogenes, the biologic significance of gene mutations, the utility of new gene therapy delivery vectors and understanding the normal cellular processes of adhesion, signaling and cell development. The Core will also assist Cancer Center members engaged in translational and clinical research by proving the technical expertise needed to evaluated the effects of a given intervention/therapy under study on the hematologic system. Available assays will provide the investigator with the ability to determine: the effects on human hematopoietic stem and progenitor cell growth in culture; immunohistochemical analysis of changes in cell surface protein display; and effects on gene expression using RT-PCR, representational analysis (RDA) and high density DNA membrane arrays. The Stem Cell Biology Core will be directed by ALAN Gewirtz, MD, Professor of Medicine and Pathology and Laboratory Medicine, who is recognized for his expertise in stem cell biology and therapeutics and has several NCI grants (RAID, PO1 and R01). Through his personal research experience as a basic, translational and clinical investigator, Dr. Gewirtz, identified the need for such a core in order to conduct innovative research. This was further reinforced by the experience of senior investigators on a PO1 that had a funded core of this type, which has greatly enhanced the quality and timeliness of the related research. Mariusz Ratajczak, MD, PhD, a long-time collaborator of Dr. Gewirtz, will assume the role of Technical Director of the facility. Together, Drs. Gewirtz and Ratajczak have more than 30 years experience in the isolation and culture of hematopoietic stem cells. Usage by Cancer Center members with peer reviewed funding is expected to be 70% of overall usage and total usage by Cancer Center members is expected to be 90% of overall usage.